can only connect to 1 camera if using bt878 wdm driver while other software can connect 4 camera

[GoogleCodeExporter]

I am using pico 2000 card with 4 inputs. Pico 2000 card is pci dvr card 
with 1 BT878 IC and 4 inputs.
iSpy can only view 1 camera through 0:video composite. If you see video input 
(in Video Source window); you will have 0:video composite; 1:video 
composite, 2:video composite; 3: video composite which corresponding to 4 video 
inputs.
I use another software "Blue Iris". "Blue iris" able to display all 4 video 
input. I click the stream format is : PAL-B, RGB-32, max frame rate : 5 fps.

Stream format can also be shown using VLC. The Steps
1. Media : open capture device
2. Click advanced options
3. click device properties and tuner properties.

I think the problem with iSpy is using Aforge directshow library
to get the video resolution. Aforge shows all video resolutions for
maximum frame per second with certain resolution but not the resolution with 
correct frame per second. Using GraphStudioNext; I can see the properties of 
directshow filter. If I insert Video Capture DirectShow Filter in 
GraphStudioNext; I can see the AvgTimePerFrame property.
If using formula from the iSpy source code : 1000000/AvgTimePerFrame is equal 
to maximum fps that the hardware can handle depending on video width and height.

Sorry for my English.

Original issue reported on code.google.com by [email protected] on 13 Mar 2013 at 1:04